Question

1 .Oblicz moc silnika samochodu ktory wykonuje prace 3MJ w czasie 5 minut wynosi :
a) 15kW
b) 10kW
c) 10MW
d) 900kW

+ rozwiazanie

Answer 1

W=3MJ = 3000000J
1MJ= 1 000000 J
t=5min = 300s
P?
P=W/t
P=3000000J/300s=10000W=10kw

Answer 2

Dane:
W = 3 MJ = 3 000 000J
t = 5min = 5 * 60s = 300s

Szukane
P = ?

P = W/t
[P] = J/s = W
P = 3000000/300
P = 10000 W
P = 10 kW

Odp: b)

Answer 3

5 min = 300 s
P = W : t = 3 MJ : 300 s = 3 000 000 J : 300 s = 10 000 W = 10 kW.
Odp. 10 kW (b )